Ah, discovered I needed wp_head() in my header.php file!! Darn theme development documentation is so thin.
Here’s another question:
Why do the children posts have no content or excerpt?
I’m seeing posts with post_parent = 0 (these must be parent posts), and I’m seeing posts with post_parent > 0 (these must be children). But the children posts were not explicitly created.
Is this a versioning scheme – the children are created when I update the original post?